Machine for applying liquid coating to articles

ABSTRACT

This machine includes a housing, conveyor means arranges to convey a continuous procession of spaced apart articles to be coated through said housing, means within the housing for applying liquid coating to the articles near the location where they enter the housing, and blower means in the housing positioned near the location where the articles pass out of the housing for directing thin flat blade like jets of air onto the coated articles to blow excess coating off of them.

United States Patent [191 Hoff [ 51 Jan. 16, 1973 6/1961 Buelow et al 54 MACHINE FOR APPLYING LIQUID 2,988,459 ...'.1 18/63 OA o ARTICLES 2,653,566 9/1953 Worden ....i 18/63 2,097,601 11/1937 Potdevin ..-..ll8/63 [76] Inventor: Glenn A. Hoff, 1019 West 65th St., 7

Seattle Wash 98107 Primary ExaminerMervin Stein [22] r Aug. 20, 970 Assistant Examiner-Leo Millstein Attorney-Fred C. Matheny [21] Appl. No.: 65,618

[57] ABSTRACT [52'] {1.8. CI. 1 18/63, 117/102, 118/316 This machine includes a housing, conveyor means [51] Int. Cl ..Bc 11/00 ranges to convey a ontinuous procession ofspaced [58] Field of Search ..1 18/63, 316, 21, 102, 103, apart articles to be coated through Said housing 118/104; 117/102 means within the housing for applying liquid coating to the articles near the location where they enter the ReterencesClted housing, and blower means in the housing positioned near the location where the articles pass out of the UNITED STATES PATENTS housing for directing thin flat blade like jets of air 3,297,469 1/1967 onto the coated articles to blow excess coating off of' 2,667,428 l/1954 them. 3,172,777 3/1965 2,332,385 /1943 Lauring ..l18/63 6 Claims, 8 Drawing Figures *1 73 T1 6/ I 74 I .52 "5 0 57 l 82 w 15,, J1 1 83 I 80 o 43 l g l M 61 e lg 79 33 37 I 1 l 42 ml 122 1 w 1 1 t 1 m l I i L L .9 1 4 3 l 1 2e M 11 1. 84 28, 1 60 /4 ll 7/ l \T.::. ;T I i l I 6/ l L l 62 I 1 I n 6.3 O 15 "I n. o i n I 6 I: T::::l. J.-

PATENTEUJAH 16 I975 SHEET 2 [1F 44 INVENfOR. Glen A. Hoff 11/) BY M3,

M Q A 772%5) PATENTEDJAN 16 I975 SHEET 3 [IF 4 INVENTOR. Glen A. Hoff BY fwd MACHINE FOR APPLYING LIQUID COATING TO ARTICLES SUMMARY OF THE INVENTION An object of my invention is to provide a simple, efficient and inexpensive machine through which articles of various shapes and sizes can be passed in a rapid and continuously moving procession and by which a smooth and evenly distributed coating of paint, varnish or similar liquid material can be applied at a substantial saving in time and labor.

Another object is to provide a machine of this type in which the loss of highly volatile thinners in the liquid coating being applied is minimized by avoiding the use of a vacuum or suction in removing excess coating from the articles which are being coated and instead using thin flat blade like jets of compressed air to blow the excess liquid coating off of the articles.

Another object is to provide a machine of this type in which articles to be coated are conveyed, preferably in spaced apart relation, through a housing wherein the articles are first coated by flooding them with the liquid coating so that all parts of the articles, including their ends and the walls of holes, recesses, and the like in the articles and projecting parts on the articles are adapted for applying paints which use water-as'a thinner to wooden articles.

Other objects of the invention will be apparent from the following description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in side elevation of a machine made in accordance with my invention.

FIG. 2 is a view in longitudinal vertical section, taken substantially on line 22 of FIG. 4, and with parts in elevation of said machine.

FIG. 3 is a view in horizontal section taken substantially on line 3-3 of FIG. 1, parts being in plan and parts being omitted. I

FIG. 4 is a view in end elevation looking in the direction indicated by line 44 of F IG., 1 and showing the discharge end of the machine.

- FIG. 5 is a vertical sectional view, with parts in elevation, taken substantially on line 5-5 of FIG. 1 and looking toward the intake end of the machine.

FIG. 6 is a view, partly in section and partly in plan,

taken substantially on line 6-6 of FIG. 1 and showing used in blowing excess liquid coating off of articles in the machine.

Like reference numerals throughout the several views. I

refer to like parts This machine comprises a lower frame and housing part 15, preferably of rectangular shape, which rests on a floor or base 16 and has a hopper shaped bottom 17 and within which is a reservoir 18 adapted to contain liquid coating. A combined filler and air vent tube 14 communicates with the upper part of the reservoir 18 and a removable cap 13 of larger size than the tube 14 is provided for use on it. The cap 13, when on the tube, overhangs said tube and the overhanging part has in it downwardly directed air vent openings 12. When the cap 13 is on the tube 14 it directs escaping air downwardly and helps to prevent vaporized liquid coating from escaping from the reservoir 18 along with the air.

An upper frame and housing part 19 is supported on I the lower frame and housing part 15 and provides a compartment through which the articles being treated or coated are moved and within which the liquid coating is applied to them. Preferably at least the top wall or cover of the upper housing part 19 is removable to afford access to the interior.

The articles to be coated are moved from left to right, FIGS. 1, 2 and 3, in a continuous procession and preferably in spaced apart relation through the upper housing part 19 by conveyor means herein shown to be an infeed belt 20, a plurality of driven feed rollers 21 to 25 inclusive, and an outfeed or discharge conveyor belt 26. Belt 26 is preferably a wire mesh belt.

Preferably, the infeed conveyor belt 20 and the feed rollers 21 to 25 are all driven by the same driving means. This means is shown in FIGS. 1 and 3 to be a motor 27 connected by belt type variable speed transmission means 28, a speed reduction gear unit 29 and a belt 30 with a shaft 31 which carries a roller 32 on which the infeed belt 20 operates. All of the feed rollers 21 to 25 are driven in the same direction and at the same rate of speed by an endless link belt 35 which passes around a sprocket wheel 34 on theshaft 31 and aroundanother sprocket wheel 35 on a shaft 36 which carries the feed roll 25 nearest to discharge belt 26. The link belt 33 engages with suitable sprocket wheels on the shafts of the rollers 21 to 25 and drives each of said rollers. Preferably idler sprocket wheels, one of which is indicated by dotted lines 37 in FIG. 1, are pro-- vided in suitable locations to hold the link belt 33 in operative engagement with the sprocket wheels on the shafts of the feed rollers 21 to 24 inclusive. Preferably a housing 33' is provided for the link belt 33 and the sprocket wheels over which it operates. This housing 33' is shown in FIG. 5 but is omitted inFlGS. l to 3.

Preferably upper housing part 19 is closed part way from its topdown at both ends. This leaves an opening 38 at the outlet end and leaves, at the inlet end, a similar opening which is curtained by a curtain 38 of fairly heavy but pliable material, such as light weight rubber belting. Curtain 38 hangs from its top edge and is easily lifted by articles passing under it and it minimizes air turbulence and helps in preventing escape of air from the inlet end of housing 19. Upper housing part 19 has a trough shaped bottom 39 within which is an elongated drain opening 40 having over it a screen 41. Excess liquid coating from upper housing part 19 drains through opening 40 back into reservoir 18.

Two liquid coating applicator pipes 42 and 43 extend crosswise of the upper housing part 19 a short distance inwardly from the inlet end of said housing part. The pipe 42 is above and the pipe 43 is below the path of movement of articles being moved through said housing part 19 on the conveyor rollers 21 to 25. Lower applicator pipe 43 extends straight across the housing 19 and is shown as being supported in tubular fittings 44 which are rigid with housing part 19 and as being rotatively adjustably held in said fittings 44 by screws 45. Said lower pipe 43 is provided with upwardly directed perforations 43' through which paint or other liquid coating is discharged upwardly onto the lower surfaces of articles carried on feed rollers 21 to 25.

The upper applicator pipe 42 is supported for vertical, angular and rotative adjustment. The means shown in FIGS. 1, and 6 for adjustably supporting said pipe 42 comprises a spherical bearing member 46 rigid with said pipe 42 and supported for rotative and tilting adjustment in a suitable spherical socket formed jointly by two plates 47 which are secured by bolts 48 to a slide plate 49. The slide plate 49 is guided for vertical movement in guide members 50 and has an adjusting rod 51 secured to it. Rod 51 extends upwardly through a guide tube 52 which is rigid with housing 19 and is adjustably clamped to tube 52 by a screw 53. This provides for vertical adjustment of pipe 42. A vertical slot 54 in the wall of housing '19 permits vertical adjustment of pipe 42. The slide plate 49 at least partially covers slot 54 and retards the escape of coating through said slot. A plurality of closely spaced apart holes, not shown but which are similar to holes 43' in pipe 43, are provided in the lower side of pipe 42 for discharge of coating.

As herein illustrated the applicator pipes 42 and 43 are respectively provided with shut off valves 55 and 56 which are positioned near housing 19 and said valves 55 and 56 are respectively connected by'flexible hoses 57 and 58 with pressure regulating valves 59 and 60. The valves 59 and 60 are connected by a pipe 61 with the discharge port of a pump 62 and the intake port of pump 62 is connected by apipe 63 with the lower portion of reservoir 18. The supply of coating to pipes 42 and 43 can be shut off and turned on by valves '55 and 56 without disturbing the adjustment of pressure regulating'valves 59 and 60.

Loosening of the nuts on bolts 48 permits universal tilting adjustment of pipe 42. This tilting adjustment of pipe 42 makes it possible to obtain a better application of coating, particularly to articles having uneven or inclined upper sides.

The provision for adjustment of applicator pipes 42 and 43 rotatively makes it possible to set these pipes so they will direct coating at different selected angles onto the articles carried on the rollers 21 to 25. If the articles on said rollers are spaced apart at least a short distance the pipes 42 and 43 can be rotatively adjusted so the discharging coating from one of these pipes will be directed onto the leading ends and the coating from the other pipe will be directed onto the trailing ends of the articles. In substantially all instances the sides of the articles will be completely covered by the coating discharged by the two pipes 42 and 43. This is true regardless of the cross sectional shape of the articles. However it will be understood that additional applicator pipes may be provided alongside of the path of travel of the articles in positions similar to those occupied by hereinafter described blower pipes 68 and 69 to direct coating onto the sides of the articles.

Means herein shown for blowing excess liquid coating 011 of the articles before they pass out of the housing 19 comprises two approximately horizontal compressed air blower pipes 66 and 67 positioned respectively above and below the path of movement of the articles and two substantially vertical blower pipes 68 and 69 positioned at the two sides of the path of movement of the articles. Each of the four blower pipes is provided with a longitudinally extending narrow air discharge slot in the side of the pipe nearest the articles. One such slot 70 is shown at the right, FIG. 2, in vertical pipe 69. Each blower pipe is adapted to direct a thin, flat, blade like jet of air onto the adjacent side of the just coated articles at an angle which depends on the rotary adjustment of the pipe to blowand strip excess coating off of the articles before they pass out of the housing.

The four blower pipes 66, 67, 68 and 69 are con nected respectively by hoses 71, 72, 73 and 74 with compressed air supply means, such as a manifold 75.

Air at a pressure preferably not in excess of 4 pounds per square inch is supplied to manifold or tank 75 by a pump P. The uppermost horizontal blower pipe 66 extends through upright slots 70 in the side walls of housing 19 and is rotatively adjustably held in fittings 79, see also FIGS. 7 and 8. A screw77' is provided to lock pipe 66 to at least one of the fittings 77. The fittings 77 are connected by pivot members 78 with forked brackets 79 on the lower ends of upright rods 80. The rods 80, one at each side of housing 19, extend upwardly through guide tubes 81 which are rigid with the housing 19. Screws 82 lock rods in desired positions of vertical adjustment to guide tubes 81. The just described supporting-devices for pipe 66 permit said pipe 66 to be rotatively adjusted by loosening screw 77' and to be vertically and angularly adjusted by vertical adjustment of rods'80 in guide tubes 81.

The pivots'78 and brackets 79 permit vertical angular adjustment of pipe 66 as illustrated by the broken lines in FIG. 8. This may be desirable in' instances where the articles passing under pipe 66 have inclined upper surfaces. Preferably a plate is carried by each tubular fitting 77 and numbered 83. Each plate 83 is positioned against the housing wall closest to it so it will cover at least part of the adjacent slot 76 and minimize the escape of air through said slot. In FIGS. 1 and 4 the uppermost blower pipe is shown in a lowermost position which it might occupy when thin articles are being coated but it will be adjusted upwardly to accomtubes 88 which are rigid with housing 19. Screws 89 adjustably secure the rods 87 in the tubes 88 and provide for vertical adjustment of blower pipe 67.

Each upright blower tube 68 and 69 extends downwardly through a fixed guide tube 90 into the housing 19 and is adjustably held in desired rotative positions by a screw 91.

An angularly adjustable baffle plate 92 is supported by pivot members 93 in the upper portion of the housing 19 a short distance in front of the four blower pipes. An arm 94, shown dotted in FIG. 2, is rigid with one of the pivots 93 and has in it an arcuate slot 95 which receives and operates on a screw 96 by which the baffle plate is held in chosen positions of adjustment. The baffle plate 92 helps in directing air downwardly over the articles which might otherwise tend to pass upwardly out of the housing.

The operation of this machine may be briefly described as follows: The infeed belt and the peripheries of the feed rollers move at the same speed. The outfeed belt can be driven by independent driving means which moves at a speed not less than the speed of the infeed belt and feed rollers. Articles long enough so they will not drop between the feed rollers and which can vary widely in shape and size are fed in end to end, preferably spaced apart relation, through the machine. As they pass the applicator pipes 42 and 43 they are flooded and completely covered with liquid coating. Excess coating which remains on the articles and is not immediately absorbed by them is blown off when they reach the blower pipes and the articles are delivered onto the outfeed conveyor with a smooth and evenly distributed layer of the coating on them.

The coating applicator pipes 42 and 43 and the blower pipes 66, 67, 68 and 69 are herein shown as being straight but it will be understood that some or all of these pipes may be shaped to conform to the cross sectional shape of articles to be coated. Pipes formed of some of the plastics are suitable for use in this machine and can be readily shaped to conform fairly closely to the shapes of sides of articles which are not flat.

By flooding the articles with the coating instead of spraying them I am able to obtain complete coverage and at the same time avoid the use of the compressed air which would be required for spraying and this simplifies the machine.

Paints which employ water as a thinner are liable to be more slowly absorbed into wooden articles than are paints using other thirinersJThis machine is well slowing down the rate of feed of the articles through the machine.

I claim:

l. A machine for applying liquid coating to articles comprising a housing having in it two spaced apart openings through'which articles to be coated enter and leave said housing; conveyor means in said housing operable in moving articles between said two openings; two liquid coating applicator pipes disposed in said housing adjacent the location where the articles enter the housing and extending across the path of travel of the articles on said conveyor means, one above and the other below said path of travel, each applicator pipe having in it liquid discharge openings directed toward the path of travel of articles on the conveyor means;

liquid coating supply means connected with said applicator pipes; two compressed air blower pipes disposed within the housing adjacent the location where the articles leave the housing, one above and the other below the path of travel of the articles on the conveyor means, each blower pipe being provided in the 'side thereof adjacent the path of travel of the articles on the conveyor means with a narrow longitudinally extending air discharge slot positioned to direct a thin flat blade like jet of air onto the articles on said conveyor means, whereby excess liquid coating is blown off of said articles; two upright compressed air blower pipes supported in the housing, one at each side of the path of travel of articles on the conveyor means and close to the two first mentioned blower pipes, each upright blower pipe having a narrow longitudinally extending slot in the side thereof next to the path of travel of articles on the conveyor, whereby thin flat blade like jets of air will be directed onto the sides of said articles; and compressed air supply means connected with all of said blower pipes.

2. The machine as claimed in claim 1 in which at least a portion of the conveyor means within the housing is formed by a plurality of spaced apart driven feed rollers.

3. The machine as claimed in claim 1 in which each first mentioned blower pipe is rotatively adjustably supported, whereby the angle of incidence of the thin flat blade like jet of air directed by it onto the articles can be adjusted.

4. The machine as claimed in claim 1 in which each first mentioned blower pipe is rotatively adjustably supported, whereby the angle of incidence of the thin flat blade like jets of air directed onto the articles by it can be varied, and in which vertically and tiltably adjustable means supports the uppermost first mentioned blower pipe for vertical and tilting adjustment of said means is carried by a wall of the housing and supports the uppermost liquid applicator pipe for vertical and universal angular adjustment relative to articles carried on the conveyor.

6. The machine as claimed in claim 1 in which an air deflector plate is supported for tilting adjustment about horizontal pivot means within the housing adjacent to the uppermost blower pipe and at the side of said uppermost blower pipe toward which articles on" the conveyor normally move. 

1. A machine for applying liquid coating to articles comprising a housing having in it two spaced apart openings through which articles to be coated enter and leave said housing; conveyor means in said housing operable in moving articles between said two openings; two liquid coating applicator pipes disposed in said housing adjacent the location where the articles enter the housing and extending across the path of travel of the articles on said conveyor means, one above and the other below said path of travel, each applicator pipe having in it liquid discharge openings directed toward the path of travel of articles on the conveyor means; liquid coating supply means connected with said applicator pipes; two compressed air blower pipes disposed within the housing adjacent the location where the articles leave the housing, one above and the other below the path of travel of the articles on the conveyor means, each blower pipe being provided in the side thereof adjacent the path of travel of the articles on the conveyor means with a narrow longitudinally extending air discharge slot positioned to direct a thin flat blade like jet of air onto the articles on said conveyor means, whereby excess liquid coating is blown off of said articles; two upright compressed air blower pipes supported in the housing, one at each side of the path of travel of articles on the conveyor means and close to the two first mentioned blower pipes, each upright blower pipe having a narrow longitudinally extending slot in the side thereof next to the path of travel of articles on the conveyor, whereby thin flat blade like jets of air will be directed onto the sides of said articles; and compressed air supply means connected with all of said blower pipes.
 2. The machine as claimed in claim 1 in which at least a portion of the conveyor means within the housing is formed by a plurality of spaced apart driven feed rollers.
 3. The machine as claimed in claim 1 in which each first mentioned blower pipe is rotatively adjustably supported, whereby the angle of incidence of the thin flat blade like jet of air directed by it onto the articles can be adjusted.
 4. The machine as claimed in claim 1 in which each first mentioned blower pipe is rotatively adjustably supported, whereby the angle of incidence of the thin flat blade like jets of air directed onto the articles by it can be varied; and in which vertically and tiltably adjustable means supports the uppermost first mentioned blower pipe for vertical and tilting adjustment of said uppermost blower pipe relative to articles on the conveyor means.
 5. The machine as claimed in claim 1 in which vertically adjustable and universally tiltably adjustable means is carried by a wall of the housing and supports the uppermosT liquid applicator pipe for vertical and universal angular adjustment relative to articles carried on the conveyor.
 6. The machine as claimed in claim 1 in which an air deflector plate is supported for tilting adjustment about horizontal pivot means within the housing adjacent to the uppermost blower pipe and at the side of said uppermost blower pipe toward which articles on the conveyor normally move. 